Center-punch.



No. 781,947 PATENTED FEB. '7, 1905. J. J. HARTLEY & J. M. STRYHAL.

CENTER PUNCH.

APPLICATION FILED JULY 15, 1904.

IN L 'N'I'UHEI UNITED STATES JAMES J. HARTLEY AND JOSEPH M. STRYHAL, OF SCHENECTAD): NEW

. Patented February '7, 1905.

PATENT EEIcE.

YORK, ASSIGNORS TO BROXVN & SHARPE MANUFAOTURING COMPANY, OF PROVIDENCE, RHODE ISLAND.

CENTER-PUNCH.

SPECIFICATION forming part of Letters Patent No. 781,947, dat d F bruary 7, 1905.

Application filed July 15, 1904. Serial No. 216,697.

To (17/ [Pit/H121 it nm/y concern:

Be it known that we, Janus J. HARTLEY and JosEru M. S'IRYHAL, citizens of the United States, residing at Schenectady, in the county 5 of Schenectady and State of New York, have invented a new and useful Improvement in (enter-Punches, of which the following is a specification.

This invention has reference to an improve- IO ment in punches, and more particularly to an improvement in automatic centering or prick punches for machinists use.

The object of our invention is to improve the construction of an automatic centering or 15 prick punch whereby the construction is simplified and the cost of manufacture is reduced.

Our invention consists in the peculiar and novel construction of an automatic centering or prick punch having a hollow cylindrical Q handle, a spring-actuated plunger or hammer in the handle, a tubular tip secured by screwing it into the open end of the handle, a springpressed pointed punch-rod in the tubular tip having a cap in which is an offset aperture, a thimble having a hole forming an inwardlyextending circular lip in its top placed intermediate the plungerand the tubular tip, forming a stop for the plunger, and a pawl pivotally secured to the plunger under spring tension adapted to enter the offset aperture in the cap on the punch-rod, said pawl having a beveled tooth adapted to engage with the edge of the otfset aperture to hold the plunger when depressing the handle and to engage ble to release the plunger which, actuated by a coiled spring, strikes the upper end of the punch-rod and drives the pointed end into the article to be centered or indented, with other 4 details of construction, as will be more fully set forth hereinafter.

Figure 1 is a side view of our improved automatic centering-punch, showing the handle broken away to more clearly show the construction of the punch. Fig. 2 is a sectional view taken lengthwise through the punch, showing the punch in its normal position in full lines and in the position it would assume with the inwardly-extending tip on the thimby depressing the handle to the point of re- Zleasing the plunger to strike the blow in 1 broken lines. Fig. 3 is a side view of the plunl ger removed from the handle, showing the means of pivotally securing the pawl to the plunger under spring tension. Fig. l is a vertical sectional view of the stop-and-pawlreleasing thimble. Fig. 5 is a side view of the tubular tip and pointed punch-rod removed t'rom the handle, showing the cap on the upper end of the punchrod broken away to clearly show the offset aperture in the cap. Fig. (i is a top view of the Sm)LPZIDKl-IHHVl-FO- leasing thimble, showing the inwardly-extending circular lip for releasing the pawl: and Fig. 7 is an upper end view of the tubular tip, cap, and punch-rod, showing the oil'- sct aperture in the cap of the pawl.

1n the drawings, 1/ indicates a hollow cylind rical handle having the closed end 1/, the internal serew-threzuled open end 11*, and the cylindrical bore a, stepped to form the shoulder a, as shown in Fig. 2. A tubular tip I), having the longitudinal hole 7/, stepped to form the shoulder /i, is secured by screwing the screw-tlu'eaded end 6 into the internal screwthreaded end a of the handle. A punch-rod c, having the pointed end 1:, and the reduced portion a, forming the shoulder 0", extends upward through the hole I) in the tip. A coiled spring w surrounds the reduced portion and abuts on the shoulder i and the washer A cap 0", lurving the offset aperture is secured by screwing it onto the protruding upper end r of the pimch-rod 1 over the washer as shown in Fig. 2. A stop-and pawl-releasing thimble (1, consisting of :1 cylindrical shell having the inwardly-exteuding circular lip r! in its top, is held in the cylindrical bore of the handle intermediate the washer and the shoulder a, as shown in Fig. 2. A cylindrical plunger w, having the recess 1 cut out of the side of the plunger to form a lip, which in turn is cut through the center to form the oppositelyalisposed lugs as shown in Figs. 2 and 3, is adapted to have a sliding lit in the bore a of the handle. A flat metal pawl f, having the beveled tooth f, the downwardly-extending ends f f adapted to enter the offset aperture 0 in the cap 0 and adjacent the upper end f the notches f f, shaped to loosely fit the lugs e e on the plunger, is pivotally held in position on the plunger by the flat spring g, secured to the plunger by the screw g. The free end of the spring g, bearing on the upper end f of the pawl, holds the pawl in its normal position under spring tension, as shown in Figs. 2 and 3. A heavy coiled spring it is placed intermediate the top of the plunger 0 and the closed end a of the handle a, as shown in Fig. 2.

When the operative parts of our improved automatic centering-punch are in their normal positions, the thimble (Z forms a stop for the plunger 6 and holds the washer 0 between the lower end of the thimble and the upper end of the tubular tip 6. The pawl f extends downward through the thimble (Z and into the offset aperture 0 in the cap 0, with the beveled tooth f on the pawl engaging with the upper outer edge of the aperture 0 in the cap.

In the operation of our improved automatic centering-punch the operator places the point 0 in position on the article to be centered or indented and depresses the handle a by pushing down on the handle. The plunger 0 isheld by the pawl f, the coiled spring 0* is compressed between the shoulder a on the punchrod 0 and the washer 0", and the spring h is compressed between the top of the plunger 6 and the closed end a of the handle. When the handle is depressed to the position as shown in broken lines in Fig. 2, the beveled tooth f on the pawlengages with the inwardlyextending lip (Z on the thimble (Z, which acting on the beveled tooth disengages the tooth on the pawl from the edge of the aperture 0 in the cap 0. The plunger 6 now descends under the impulse of the coiled spring 71 and strikes a blow on the protruding upper end 0 of the punch-rod, forcing the point 0 of the punch-rod into the article to be centered or indented. As the plunger e descends to strike the blow 'the pawl f passes through the ofiiset aperture 0 in the cap 0. When the pressure on the handle is released, the plunger 0 comes to a stop on the thimble (Z, the handle rises to its normal position by the tension of the coiled spring 0, and the pawl f, acting under the tension of the spring 9, moves outward to bring the tooth f on the pawl into engagement with the upper outer edge of the aperture c in the cap a when the handle has reached its upward limit and brought the cap a into its normal position, as shown in Fig. 2.

Having thus described our invention, we claim as new and desire to secure by Letters Patent we 1. An automatic center-punch having a hollow cylindrical handle closed at one end, a tubular tip secured to the open end of the handle, a spring-pressed punch-rod in the tubular tip, aspring-actuated plunger in the handle, a pawl pivotally secured to the plunger under spring tension, a tooth on the pawl, a cap on the upper end of the punch-rod in which is an offset aperture, and a thimble having an inwardlyextending lip adapted to form a stop for the plunger and to release the pawl, as described.

2. In an automatic center-punch, the combination of ahollow cylindrical handle closed at one end, a tubular tip secured to the open end of the handle, a shouldered punch-rod in the tubular tip, a washer on the upper end of the tubular tip, a coiled spring on the punchrod intermediate the shoulder and the washer, a cap having an offset aperture secured to the upper end of the punch-rod, a thimble having an inwardly-extending lip in the handle, a cylindrical plunger in the handle, a pawl having a beveled tooth pivotally secured under spring tension to the plunger, and a coiled spring intermediate the plunger and the closed end of the handle, as described.

3. In an automatic center-punch, the combination of a hollow cylindrical handle ct, a tubular tip 7), a punch-rod 0, a coiled spring 0*, a washer 0", a cap 0, a stop-and-pawl-releasing thimble (Z, a cylindrical plunger (1, a flat metal pawl f, a flat spring g, and a coiled spring A, all constructed and for the purpose as described.

In testimony whereof we have hereunto signed our names to this specification in the presence of two subscribing witnesses.

JAMES J. HARTLEY. JOSEPH M. STRYHAL.

\Vitnesses:

Gr. 0. HOLLISTER, J. F. BARTLETT. 

